Already in the early stage of a ship newbuilding project it is worth spending detailed thoughts on the planned model test scope. Apart from the standard test scope for the hull and propeller design - which should cover all aspects needed for the sea trial evaluation as well as the Energy Efficiency Design Index EEDI evaluation - it should be considered if additional tests, e.g. with competing rudder designs, competing propeller designs or energy saving devices, shall be performed. With the experience in project planning Schiffbauingenieure Hamburg can help finding the optimal stage within the model test phase to perform these tests. Having considered these aspects from the very beginning can save time and money in the end.

Long before the introduction of the Energy Efficiency Design Index EEDI all different kinds of propulsion improvement devices and energy saving devices have entered the ship building market. To name but a few, there are twisted rudders, rudder bulbs with customised hub caps, rudder fins, propeller boss cap fins, ducts, stators, saver fins. During her time at HSVA Grete Ernst has performed model tests with all these devices and has a picture of their potentials. With the knowledge about the capabilities but also the limitations of model testing in relation to energy saving devices Schiffbauingenieure Hamburg can help finding the optimal test scope.

Besides the calm water performance tests most model basins offer additional types of tests to get a more complete picture of the ship’s performance in operation. The possible test scope includes for example trim optimisation tests, manoeuvring tests, tests in seaway and tests in ice. Schiffbauingenieure Hamburg can report on these types of tests, highlight the potentials and limitations to decide if additional tests might be useful for the current project.

When model tests are carried out Schiffbauingenieure Hamburg can send an expert to attend the tests to witness the procedure on behalf of the owner. Especially when performing optimisation tests with energy saving devices usually a lot of different model settings have to be tested and the results of the measurements have to be judged immediately on site. Being experienced in this procedure, Schiffbauingenieure Hamburg can assist in interpreting the results of the measurements and can give decision guidance for the optimisation process.

The performance of the model tests, however, is just one aspect of model testing. The scaling of the measured data to get to the full scale performance prediction is an elaborate process. All model basins are using similar but slightly different methods for the scaling which can be confusing, especially when comparing test results from different model basins. Just a few parameters – such as hull roughness - that are influencing the final prediction result, can be defined by the customer. Schiffbauingenieure Hamburg can assist in understanding the test report and the scaling procedure behind it and show the crucial parameters.

The final verification of the model test prediction takes place when the vessel is going on sea trials. With the introduction of the EEDI more restrictions and recommendations to the sea trial procedure have been formulated. With the experience in sea trial evaluation Schiffbauingenieure Hamburg can help defining the optimal scope for the trials for the arrangements with the yard. Furthermore, Schiffbauingenieure Hamburg can send an expert to attend the trials to witness and protocol the compliance of the appointed procedure.